Sorry for the delay in answering questions, and the questions are good.
The latest Info on the AFCI and the listing test were presented to me by someone from UL. I believe his name is Warren ?, but I am remote from my office until Tuesday when I would be able to check.
Does the AFCI test button place an arc signature for the test? I don't know, this is a question I haven't asked. I was led to believe this was the case and thus I did not inquire directly. Yes, we are required to trust UL and the manufacturer that enough testing has gone into these to ensure the test button does work. UL is most adamant that this is the only true test of the circuitry (outside of a testing lab facility).
If I were the engineer assigned by a company to test a device as complex as these, would I do so by creating a fault? NO! I would not want the liability of burning down a structure when the thing failed. So, how would I test them? As I would have knowledge of the circuitry inside and out, I could design tests that would check out the complete circuitry and verify that it is working properly without subjecting it to a full blown hazardous test.
Anyway, I would not want to be holding a handheld tester with a 75 amp arc developing in it, especially if the device did not trip.
I can only guess as to why they are not available yet. As they are listed, you would think that someone would want to buy them for the additional safety. Could be Square D is being cautious and doing additional testing to avoid another recall. We can hope this is the case.
There are typical times in the life of an electrical system where things are more likely to burn down due to an arc in the distribution system.
1- When first built.
2- When ever new occupants move in based on the next item.
3- When remodeling or hanging things. And within about 2 years of any of the above.
You can all think of other items to add to this list. The AFCI are designed to help protect against these problems. They will not protect against all, or catch all. They add an additional level of safety that according to statistics (yes, I know there are some problems with these statistics) show is significant. If these statistics were from manufactures and not outside national fire agencies (I do not remember who), I would not trust them as much.
What about the 30 year old homes? Do they need protecting? You decide. Ul's project of examining old wiring has shown preliminarily that it is still functioning as designed and manufactured. I for one have given electricians more work by highly recommending service changeouts and in 2-wire homes I wish more manufacturers had a GFCI-AFCI device like Cutler-Hammer so I could avoid more attic and crawl spaces.
As for functioning after a giving service, I can not comment. I have read the report on GFCI's. I recommend that every service has surge protection installed and that we all test devices per manufacturers instructions. That is also why newly manufactured GFCI's have better circuitry to prevent operation after test failure.
Nuisance Tripping? I hear you Ryan. Using simile, I would rather work on a 200 MHz pentium that was 100 percent reliable, than a 10 GHz Pentuim X that had to reboot every 15 minutes. I hope that if Code requires this for 2008, that technology quickly catches up (like in Fall 2006). Look at the black eye they got with GFCI's, I hope that they have learned that lesson well.
Let's look also at other safety issues coming up as proposals, like tamper proof receptacles. Look at the cost it will add. Do I support it? Absolutely. It gets rid of all those silly plastic inserts that you need fingers of a three year old inorder to remove. Do I want to pay for them? No, I don't think I can afford it. Do I sound lame?
Now if you will excuse me, I need to go exerise my breakers and test all my GFCI's for the first time in 11 years. Oh, I take that back, my son regulary tests the GFCI receptacle on my kitchen island. Will someone help me remove this plastic thingy so I can plug in my vacuum?
Shane, P.E.
